Square Four tyre pressures?

[john.bebb]

Hi Folks; - please can anyone advise on the recommended tyre pressures for a Mk1 (1949) Square Four? - thank you.

[adrie.degraaff]

It is depending on your tires, some have the pressure writen on it.

[markus.nikot]

I'm running mine with 2,5bar, Avon Speedmaster

Markus

[john.bebb]

Hi Markus -both front and back?

[nevhunter]

Bar is 14.7 psi 2 bar should be enough. Tyre section makes a difference. The bigger the less pressure required. Nev

[brenton.roy]

John, I think it depends on how you want the bike to feel. The 4.00 rear tyre was big for its time and I suspect it was run at low pressure for the softer ride that would give. I think this is also the reason for the 'wallows at speed' comments about square fours in old road tests. 30psi is a good starting point with new tyres.

[john.bebb]

Hi All; - I settled for 32f 36r - zero tail wallow but a bit harsh on the front -so I'll try it on 30f.
Dunlop "Roadmaster" TT100's

[Thoward]

Hi, I inflated to 30psi in the front and 32psi in the back, seems ok with normal riding on the A184 in Essex. I only weigh 10 stone, so depends on the load I guess. I have Avon speed-masters fitted, in good condition, well, almost new in fact.
Cheers

[john.bebb]

Hi Folks,
A few further thoughts on tyre pressures; - modern tyres are built to a far more advanced structure than those back in the 30's thru 50's.
Materials, construction & tread patterns have changed as also have the majority of road surfaces... (some of these have not stood the tests of time quite so well as some of our motorcycles!... nor are some roads maintained as one might hope...).
As an additional guide as to what pressurese are correct - take it for a long (>50mile) & dry reasonably hard drive... the moment you park up at the end; - gloves off & cup your hands over the treads - both should be slightly warm & tacky - neither stone cold nor "Ouch" too hot. Front should be slightly cooler as it's not involved so much in power transmission...
Such is only a guide and I politely remind all that measured tyre pressures are only relevant when measured cold - before vehicle use!
Cheers, John.

[allan.walker]

Another point regarding modern tyre compounds. From what I have seen, modern tyres seem to need higher inflation pressures than the motorcycle manufacturers recommended in their handbooks in the 50's and 60's.

Therefore, it pays to go on the tyre manufacturers website and check the pressure ranges that they advise.